CC BY-NC-ND 4.0 · Arq Neuropsiquiatr 2022; 80(04): 410-423
DOI: 10.1590/0004-282X-ANP-2021-0035
Articles

Traumatic brain injury in Brazil: an epidemiological study and systematic review of the literature

Traumatismo cranioencefálico no Brasil: um estudo epidemiológico e uma revisão sistemática da literatura
1   Universidade Federal de Minas Gerais, Faculdade de Medicina, Laboratório Interdisciplinar de Investigação Médica, Belo Horizonte MG, Brazil.
,
1   Universidade Federal de Minas Gerais, Faculdade de Medicina, Laboratório Interdisciplinar de Investigação Médica, Belo Horizonte MG, Brazil.
,
1   Universidade Federal de Minas Gerais, Faculdade de Medicina, Laboratório Interdisciplinar de Investigação Médica, Belo Horizonte MG, Brazil.
,
1   Universidade Federal de Minas Gerais, Faculdade de Medicina, Laboratório Interdisciplinar de Investigação Médica, Belo Horizonte MG, Brazil.
2   University of Texas Health Science Center at Houston, McGovern Medical School, Texas, USA.
,
3   Fundacção Hospitalar do Estado de Minas Gerais, Hospital Joaão XXIII, Belo Horizonte MG, Brazil.
,
1   Universidade Federal de Minas Gerais, Faculdade de Medicina, Laboratório Interdisciplinar de Investigação Médica, Belo Horizonte MG, Brazil.
,
1   Universidade Federal de Minas Gerais, Faculdade de Medicina, Laboratório Interdisciplinar de Investigação Médica, Belo Horizonte MG, Brazil.
4   Universidade Federal de Minas Gerais, Instituto de Ciências Biológicas, Departamento de Morfologia, Laboratório de Neurobiologia, Belo Horizonte MG, Brazil.
,
2   University of Texas Health Science Center at Houston, McGovern Medical School, Texas, USA.
5   Santa Casa Belo Horizonte, Ensino e Pesquisa, Belo Horizonte MG, Brazil.
› Author Affiliations
Support: This article received financial support from 2016 NARSAD Young Investigator Grant from Brain & Behavior Research Foundation (grant #25414), 2019 “For Women in Science”- L’Oreal Brazil-UNESCO- Brazilian Academy of Science (ABC), FAPEMIG (Fundacção de Amparo aà Pesquisa do Estado de Minas Gerais, Brazil), CNPq (Conselho Nacional de Desenvolvimento Cientiífico e Tecnoloígico, Brazil) and CAPES (Coordenacção de Aperfeicçoamento de Pessoal de Niível Superior).
 

ABSTRACT

Background: Traumatic brain injury (TBI) is a serious public health problem worldwide. Although TBI is common in developing countries, there are few epidemiological studies. Objective: To investigate the sociodemographic and clinical features of patients with TBI at the Hospital João XXIII, a public reference center for trauma in Belo Horizonte, Brazil, and to systematically review the available literature on TBI in Brazil. Methods: Clinical and sociodemographic data were collected from electronic medical records for the entire month of July 2016. The literature on epidemiology of TBI in Brazil was systematically reviewed using MeSH/DeCS descriptors in the PubMed and Lilacs databases. Results: Most patients admitted with TBI were male and under 60 years of age. Mild TBI was the most prevalent form and the most common cause of TBI was falls. A Glasgow Coma Scale score below 12, neuroimaging changes on computer tomography, and presence of any medical conditions were significantly associated with longer hospital stay. Brazilian studies showed that TBI affected mainly men and young adults. In addition, mild TBI was the most common TBI severity reported and the most common causes were motor vehicle accidents and falls. Conclusions: Overall, the profile of TBI in this center reflects the data from other Brazilian studies.


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RESUMO

Antecedentes: O traumatismo cranioencefálico (TCE) representa, mundialmente, um problema sério de saúde pública. Apesar de o TCE ser prevalente em países em desenvolvimento, estudos epidemiológicos permanecem escassos. Objetivo: Investigar as características sociodemográficas e clínicas de pacientes acometidos por TCE no Hospital João XXIII - centro de referência em trauma situado em Belo Horizonte, Brasil - e revisar sistematicamente toda a literatura disponível sobre o TCE no Brasil. Métodos: Os dados clínicos e sociodemográficos foram coletados apenas para o mês de julho, 2016, por meio de prontuários eletrônicos. A literatura sobre a epidemiologia do TCE no Brasil foi sistematicamente revisada usando descritores Medical Subject Headings (MeSH)/Descritores em Ciências da Saúde (DeCS) nos bancos de dados PubMed e Literatura Latino-Americana e do Caribe em Ciências da Saúde (Lilacs). Resultados: Os pacientes acometidos por TCE eram em sua maioria homens com menos de 60 anos. O TCE leve foi a gravidade mais prevalente entre os casos. O TCE foi causado principalmente por quedas. Escores menores que 12 na escala de Coma de Glasgow mais alterações de neuroimagem em tomografia computadorizada e a presença de qualquer comorbidade médica estão significativamente associados à maior estadia hospitalar. Estudos brasileiros demonstraram que o TCE acomete principalmente homens e adultos jovens. Além disso, o TCE leve foi a gravidade mais comum reportada, e os mecanismos de TCE mais comuns foram acidentes automobilísticos e quedas. Conclusões: O perfil de pacientes acometidos por TCE no centro de referência em questão reflete os dados de outros estudos brasileiros.


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INTRODUCTION

Traumatic brain injury (TBI) is defined as an injury caused by external force to the head that results in an anatomical lesion or functional impairment of cranial or encephalic structures. TBI is the leading cause of morbidity and mortality in polytrauma patients and is one of the main causes of death in individuals under 45 years of age[1],[2],[3]. TBI can have a variety of causes, from falls to car accidents.

Because of its medical and socioeconomic burden, TBI is a major public health problem worldwide. In the United States, 2.8 million emergency department visits were due to TBI and approximately 124,000 of the most severe cases develop long-term impairment[4],[5]. In a single North American state, the annual direct medical cost of TBI was estimated at $95 million, or $1.67 million per 100,000 people[6]. Although lifetime costs for patients with TBI vary according to their demographic characteristics, the costs in Canadian dollars (CAD) for nonfatal cases was estimated at $2,318 for males and $2,200 for females[6]. In Europe, TBI accounted for 37% of all injury-related deaths and was estimated to cost a total of €22,907 million in 2010[7],[8]. Limited demographic and socioeconomic information on TBI is available from developing countries[9].

Although TBI is widespread in Brazil and seems to have an economic and social impact, there are very few epidemiological studies [10],[11]. A previous study reported that 40% of deaths in patients aged 5 to 9 years in Brazil are due to TBI and that for every patient who dies, there are at least another three more patients with long-term sequelae[12]. In addition, the annual cost of hospitalizations due to TBI has been estimated at approximately R$ 156,300,000 (US$ 70,960,000)[11]. Unfortunately, these estimates may not reflect the actual Brazilian reality, due in part to a high rate of unreported cases associated with immediate death and the absence of a nearby emergency unit[11],[13],[14]. Furthermore, reliable quantification of the impact caused by TBI is usually not accurate because measurements are not standardized and data collection on the incidence and outcome of brain injury is incomplete. Therefore, clinical-epidemiological studies are urgently needed to systematically investigate TBI in Brazil.

The current study aimed to investigate sociodemographic and clinical characteristics of patients admitted to João XXIII Hospital with TBI and to identify factors that may influence TBI morbidity and mortality. Also, the epidemiological data available on TBI in Brazil was systematically review.


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METHODS

Original report

This was an observational study conducted at the Joao XXIII Hospital. This hospital is the main trauma center in the Metropolitan region of Belo Horizonte, the third largest metropolitan region in Brazil with more than five million inhabitants. The study was approved by the Human Research Ethics Committee of the Federal University of Minas Gerais (COEP-UFMG).

All records of patients admitted to the Emergency Department of the Joao XXIII Hospital within one month (July 2016) were evaluated using a structured protocol to obtain sociodemographic and clinical information. The sociodemographic data included: (i) sex, (ii) ethnicity, (iii) marital status, (iv) place of residence (Belo Horizonte, metropolitan area, rural area), and (v) educational level. Clinical variables included TBI features (Glasgow Coma Scale Score [GCS], CT neuroimaging changes, hemodynamic instability, and ventilatory support) and hospital outcome. The following premorbid variables were also recorded: (i) clinical comorbidities (any medical conditions that were either secondary to the TBI or that the patient already had on admission) and (ii) alcohol or illicit drug use (assessed via medical record). The causes, severity, and type of TBI were also recorded. Neuroimaging results were included when available.

Exclusion criteria included: (i) follow-up patients, (ii) non-TBI patients (evaluated via the absence of a TBI diagnosis on record), (iii) burn victims, (iv) exogenous intoxications, (v) venomous animal bites, (vi) trauma patients without TBI, and (vii) patients admitted 24 hours after TBI.

Statistical analyses were conducted with Statistical Package for the Social Sciences (SPSS) software, version 17.0. Chi-squared analyses were performed to determine statistically significant frequencies of specific events in subgroups. Binary logistic regression using a backward elimination approach was performed to determine which variables were significantly associated with a longer hospital stay, defined as more than 24 hours, as opposed to patients discharged within 24 hours after hospital admission. At the João XXIII Hospital, patients whose state of consciousness remained stable for 24 hours were discharged. The following variables were included in the initial model: age, sex, GCS score (greater than or equal to 13 or less than 12), comorbidity (presence or absence), neuroimaging changes in computed tomography, and alcohol and drug use. Stepwise backward selection was performed automatically using the SPSS software, version 17.0 (SPSS Inc., Chicago, IL, USA), and exclusion testing was done with the likelihood ratio based on the conditional parameter estimates. The goodness of fit of the logistic regression model was assessed using the Hosmer-Lemeshow test and a Receiver Operating Characteristic (ROC) curve.


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Systematic review

A systematic search for TBI studies in Brazil was performed independently by two authors (JLVMB and ASM) in the PubMED and Lilacs databases using the MeSH/DeCS descriptors for *traumatic brain injury, *epidemiology, and *Brazil. The inclusion criteria were as follows: (i) studies evaluating sociodemographic and clinical information on TBI cases in Brazil, (ii) original articles, and (iii) articles in Portuguese, Spanish, or English.


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RESULTS

In July 2016, 6,184 patients were admitted to the hospital, with 490 individuals diagnosed with TBI. These 490 individuals accounted for 7.92% of the total admissions during the research period. Four hundred seventy-seven records had enough information to determine clinical outcome by age, while 436 records contained all information required by our research protocol (data not shown).

Male patients formed the majority of our sample (n=324, 66.1%). Most TBI occurred in adults (n=259, 52.9%). The most common mechanism for TBI was an unspecified fall (n=124, 25.3%), followed by a fall from one’s own height (n=118, 24.1%) ([Table 1]).

Table 1

Sociodemographic data of the 490 available traumatic brain injury records.

n

%

Sex

Male

324

66.1

Female

166

33.9

Origin

Belo Horizonte

341

69.9

Metropolitan region

107

21.8

Metropolitan region outskirts

4

0.8

Outside metropolitan region (but still within the state of Minas Gerais)

29

5.9

Different State

2

0.4

Not informed

7

1.4

Age

0-18 years

149

30.4

19-59 years

259

52.9

60 years or more

82

16.7

Race

Brown

336

68.6

White

114

23.3

Black

32

6.5

Not informed

8

1.6

Outcome

Death

15

3.1

Discharge<24h

367

74.9

Discharge >24h

95

19.4

Hospitalized

7

1.4

Not informed

6

1.2

TBI mechanism

Unspecified fall

124

25.3

Fall from own height

118

24.1

Fall from superior height

43

8.8

Aggression

61

12.4

Firearm

6

1.2

Hit or struck by a car

45

9.2

Traffic collision

66

13.5

Non-traffic-related collision

16

3.3

Repetitive TBI

4

0.8

Not informed

7

1.4

TBI: traumatic brain injury.


The consequences of TBI differed considerably between age ranges (p=0.031). Deaths by age range were: (i) ≤18 years old, 1 death/112 individuals (0.89%), (ii) 19-59 years old, 7 deaths/245 individuals (2.9%), and (iii) ≥60 years old, 6 deaths/79 individuals, (7.6%). For the latter analysis, we considered only the 436 records that contained all the data required by our research protocol.

Patients with TBI were divided into three groups based on their GCS score on hospital admission. Patients who had GSC scores of 13-15 on hospital admission were classified as “mild TBI”. Patients with GSC scores of 9-12 and 3-8 were classified as “moderate TBI” and “severe TBI”, respectively[11],[13]. Patients with mild TBI accounted for the majority of TBI-related admissions and comprised 87.4% of the total number of TBI cases. Moderate and severe TBI cases accounted for 5.5 and 7.1% of TBI cases, respectively.

Next, we analyzed the mechanisms involved in TBI. The mechanisms of TBI were differed significantly between the different severity categories of TBI. Unspecified fall and traffic accident were the most frequent mechanisms for mild and severe TBI, respectively (data not shown).

Male patients were the most affected by TBI across severity levels (p=0.022). We also analyzed the incidence of comorbidities, CT neuroimaging changes, hemodynamic instability, ventilatory support, and death across TBI severity levels ([Table 2]). Severe TBI accounted for the majority of deaths (57.1%), whereas mild and moderate TBI accounted for 21.4% each. These deaths were related to TBI or TBI-associated injuries.

Table 2

Clinical variables across different traumatic brain injury severities.

GCS Score

p-value

Mild (13 to 15)

Moderate (12 to 9)

Severe (8 to 3)

Sex

Male

240 (63%)

19 (20.1%)

5 (16.1%)

0.022

Female

141 (37%)

5 (79.2%)

26 (83.9%)

Use of drugs

12 (3.1%)

2 (8.7%)

1 (3.2%)

0.36

Alcohol

71 (18.6%)

9 (37.5%)

3 (9.7%)

0.029

Comorbidity

95 (25%)

6 (25%)

2 (6.5%)

0.065

CT neuroimaging findings

39 (11.7%)

13 (54.2%)

24 (77.4%)

<0.001

Hemodynamic instability

0 (0%)

2 (8.3%)

4 (13.8%)

<0.001

Ventilation Support

4 (1.1%)

6 (25%)

24 (80%)

<0.001

Outcome

Death

3 (0.8%)

3 (13.6%)

8 (29.6%)

<0.001

Discharge>24h

61 (16.3%)

12 (54.5%)

16 (59.3%)

Discharge<24h

311 (82.9%)

7 (31.8%)

3(11.1%)

GCS: Glasgow coma scale; TBI: traumatic brain injury; CT: computed tomography.


In multivariate analysis, CT neuroimaging changes, the presence of medical comorbidities, and a GCS score of 12 or less remained as significant factors associated with longer hospital stay (>24h). The results are presented in [Table 3]. The logistic regression model was significant [Hosmer-Lemeshow goodness of fit test (step 5): chi-square=3.177; p=0.204] and predicted variability yielded an area under the curve (AUC) of 0.819 in the ROC analysis ([Figure 1]).

Table 3

Logistic model analysis to predict hospital admission for more than 24 hours.

Predictive variable

B

SE

Wald

df

p-value

OR

95%CI for OR

Lower

Upper

CT neuroimaging changes

-2.909

0.378

59.220

1

0.000

0.055

0.026

0.114

Medical comorbidity

-0.703

0.347

4.115

1

0.043

0.495

0.251

0.977

GCS score

-1.838

0.491

13.998

1

0.000

0.159

0.061

0.417

CT: computed tomography; GCS: Glasgow coma scale; B: beta coefficient; SE: standard error; df: degrees of freedom; OR: Odds Ratio; 95%CI: 95% confidence interval.


Zoom Image
Figure 1 ROC curve of the logistic regression model (AUC=0.819).

In our systematic review, we first identified 148 possible titles in the PubMED and Lilacs databases. Four articles were duplicates, and 114 studies were excluded after title/abstract screening. Of these 114 articles, we set aside one review for further reference screening. Thirty articles were fully analyzed, and 10 of these either did not meet our inclusion criteria or did not contain the required information. Two additional articles were identified in the references of review studies. Also, five additional articles were identified while reading the selected manuscripts, giving us a total of 27 eligible articles ([Figure 2]).

Zoom Image
Figure 2 Flowchart of study selection process.TBI: traumatic brain injury.

Most studies were conducted in cities in the state of São Paulo (n=6)[15],[16],[17],[18],[19],[20]. Three studies dealt exclusively with epidemiological data on patients who developed specific sequelae as a result of TBI, including diffuse axonal injury, intracranial hypertension, and hypoxic brain damage[15],[21],[22]. Two studies addressed epidemiological data on patients affected by specific TBI mechanisms, such as falls from their own height and firearm bullets[19],[23]. In most studies, mild TBI was found to be the most prevalent type (n=10)[16],[17],[23] - [30]. Additionally, young men were most commonly affected in all studies[11],[15] - [40]. There was limited information on ethnicity, with only three studies providing this information[11],[15],[35]. Traffic/vehicle accidents were the most common mechanism for TBI, followed by falls[15] - [17],[19],[21],[24] - [31],[33] - [40]. This information is presented in [Table 4].

Table 4

Sociodemographic characteristics of Brazilian epidemiological studies on traumatic brain injury.

Reference

Location

Study design

TBI severity/type

Most Common TBI severity (if applicable)

Male

Female

Most afflicted age group

Most afflicted ethnicity

Death

Most common TBI mechanism

n

%

n

%

Melo et al., 2019[24]

Parnaíba, Piauí, Brazil

Retrospective and Descriptive

General

Mild, n=50 (42.7%)

94

80.3%

23

19.7%

Mean age: 33.17 years (SD±17.2)

Not informed

Not informed

Automobile accidents, n=96 (82.1%)

Marinho et al., 2017[31]

Natal, Rio Grande do Norte, Brazil

Cross-sectional

General

Moderate, n=228 (61.3%)

317

85.2%

55

14.8%

18-30 years old, n=209 (56.2%)

Not informed

Not informed

Automobile accidents, n=95 (25.6%)

De Almeida et al., 2016[11]

Not applicable

Cross-sectional

General

Not informed

97,552 (mean per year)

77.7% (mean per year)

28,017 (mean per year)

22.3 (mean per year)

20-29 years old, n=28,905.4 (mean per year)

Mixed race, n=3,142,782.4* (mean per year)

*Greater number of cases because data were missing

n=9,714 (7.7%)(mean per year)

Not informed

Vieira et al., 2016[15]

São Paulo, São Paulo, Brazil

Prospective Cohort Study

Severe TBI with diffuse axonal injury

Not applicable

70

89.7%

8

10.3%

18-28 years old, n=34 (43.6%)

White, n=51 (65.4%)

n=24 (30.8%)

Traffic accidents, n=65 (83.3%)

Tavares et al., 2014[32]

Distrito Federal, Brasília, Brazil

Cross-sectional

General

Severe, n=108 (55.7%)

161

82.99%

33

17.01%

21-40 years old, n=67 (34.5%)

Not informed

Not informed

Physical aggression, n=57 (29.4%)

De Souza et al., 2013[19]

São Paulo, São Paulo, Brazil

Cross-sectional

General TBI caused by firearm projectiles

Severe, n=68 (37.6%)

154

85%

27

15%

21-30 years old, (47%)

Not informed

Not informed

Not applicable

Santos et al., 2013[25]

Pelotas, Rio Grande do Sul, Brazil

Epidemiological, Descriptive, and Retrospective

General

Mild, n=202 (40.7%)

314

63.3%

182

36.7%

0-15 years old, n=220 (44.3%)

Not informed

n=2 (0.4%)

Falls, n=233 (47.0%)

Fernandes et al., 2013[33]

Not applicable

Cross-sectional, descriptive

General

Not informed

358,780

81.5%

81,706

18.5%

14-34 years old, n=231,827 (53.0%)

Not informed

n=52,087 (12.0%)

Falls, n=154,170 (35.0%)

Carvalho Viégas et al., 2013[34]

Ananindeua, Pará, Brazil

Epidemiological, Cross-sectional, observational

General

Not informed

220

88%

30

12%

20-30 years old, n=81 (32.4%)

Not informed

n=55 (22%)

Traffic accidents, n=91 (36.4%)

Ruy and Rosa, 2011[35]

Criciúma, Santa Catarina, Brazil

Cross-sectional, descriptive, retrospective

General

Severe, n=63 (67.7%)

82

88.2%

11

11.8%

Mean age: 34.6 years (SD±16.7)

White n=84 (90.3%)

n=25 (26.9%)

Automobile accidents, n=52 (55.9%)

Moura et al., 2011[26]

Petrolina, Pernambuco, Brazil

Cross-sectional, epidemiological

General

Mild, n=54 (53.47%)

87

86.14%

14

13.86%

21-40 years old, n=52 (51.49%)

Not informed

n=8 (7.92%)

Motorcycle accident, n=45 (44.55%)

Ramos et al., 2010[36]

Caruaru, Pernambuco, Brazil

Document-based

General

Not informed

139

81.2%

32

18.7%

25-49 years old, n=56 (29.9%)

Not informed

Not informed

Motorcycle accident, n=34 (19.9%)

Guerra et al., 2010[21]

Belo Horizonte, Minas Gerais, Brazil

Retrospective cohort study

General TBI patients who developed intracranial hypertension

Severe, n=132 (100%)

89

67.4%

43

32.6%

7-9 years old

Not informed

n=68 (51.5%)

Getting hit by a vehicle, n=68 (51.5%)

Martins et al., 2009[37]

Florianópolis, Santa Catarina, Brazil

Prospective

Severe

Not applicable

631

84%

117

15.6%

Mean age: 34.8 years old (SD±16.3)

Not informed

n=249 (33.3%)

Road accident, n=225 (30.1%)

Braga et al., 2008[23]

Florianópolis, Santa Catarina, Brazil

Prospective

General TBI caused by one’s own height

Mild, n=69 (90.7%)

44

57.9%

32

42.1%

Mean age for men: 44.7 years

Mean age for women: 47.2

Not informed

Not informed

Not applicable

Faria et al., 2008[38]

Uberlândia, Minas Gerais, Brazil

Epidemiological, Prospective

General (Severe and moderate were grouped together)

Severe and moderate (grouped together), n=56 (66.7%)

68

80.9%

16

19.1%

Mean age for severe and moderate: 40.6 years

Mean age for mild: 34.8

Not informed

Not informed

Transport accidents, n=54 (64.74%)

Pereira et al., 2006[27]

Aracaju, Sergipe, Brazil

Longitudinal Prospective

General

Mild, n=422 (89%)

344

73%

126

27%

10-29 years old

Not informed

n=3 (0.6%)

Accidental fall, n=148 (31.5%)

Melo et al., 2006[28]

Salvador, Bahia, Brazil

Cross-sectional descriptive

General

Mild, n=249 (63.8%)

280

71.8%

110

28.2%

Not applicable

(Study conducted on a specific group age (0-19 years old)

Not informed

Not informed

Fall from height, n=134 (34.4%)

Melo et al., 2004[29]

Salvador, Bahia, Brazil

Cross-sectional

General

Mild, n=146 (38.4%)

460

82.9%

95

17.1%

21-30 years old, n=128 (23.2%)

Not informed

n=127 (22.9%)

Traffic accidents, n=226 (40.7%)

Dantas Filho et al., 2004[39]

Campinas, São Paulo, Brazil

Cross-sectional

Severe

Not applicable

166

80.58%

40

19.42%

Mean age: 29.21 years old

Not informed

n=75 (36.40%)

Traffic accidents, n=147 (71.36%)

Gusmão et al., 2002[22]

Belo Horizonte, Minas Gerais, Brazil

Prospective

Fatal TBI victims

Not applicable

90

75.0%

30

25.0%

Mean age: 37.5 years old (SD±18.3)

Not informed

Not applicable (Post-mortem study)

Not applicable (all patients came from traffic accidents)

Koizumi et al., 2001[40]

Not applicable

Cross-sectional

General

Not informed

10,251

62.6%

6,125

37.4%

(Study conducted on children who were ≥ 10 years old)

0-4 years old, n=9,302 (56.8%)

Not informed

n=332 (2.0%)

Falls, n=10,022 (61.2%)

Koizumi et al., 2000[20]

São Paulo, São Paulo, Brazil

Cross-sectional, retrospective

General

Not informed

2784

76.6%

851

23.41%

≤10 years old (20.3%)

Not informed

n=371 (10.2%)

Aggression, n=1,767 (48.6%)

Colli et al., 1997[16]

Ribeirão Preto, São Paulo, Brazil

Cross-sectional

General

Mild, n=2,584 (74.5%)

2476

71.4%

992

28.6%

0-10 years old

(about 30% of all men about 10% of all women)

Not informed

n=209 (6%)

Traffic accidents, n=1,241(35.8%)

Gennari et al., 1995[17]

São Paulo, Brazil

Prospective

General

Mild, n=47 (47%)

85

85%

15

15%

Closed head injury patients’ mean age: 35.4 years old

Penetrating head injury patients’ mean age: 27.2 years old

Not informed

n=12 (12%)

Traffic accidents, n=40 (40%)

Masini et al., 1994[30]

Distrito Federal, Brazil

Retrospective

General

Mild, n=76 (76%)

(Independent 100 people sample)

65

(Independent 100 people sample)

65%

(Independent 100 people sample)

35

(Independent 100 people sample)

35%

(Independent 100 people sample)

1-30 years old, n=72 (72%)

(Independent 100 people sample)

Not informed

n=797 (14.7%)

Traffic accident, n=2391 (44%)

Maset et al., 1993[18]

Sao Jose do Rio Preto, São Paulo, Brazil

Cross-sectional

General

Not informed

759

70.0%

325

30.0%

20-29 years old, n=303 (28.0%)

Not informed

Full text was not retrievable

Full text was not retrievable

We also extracted information on the consequences of TBI, patients’ clinical comorbidities, length of hospital stay, and alcohol consumption ([Table 5]). Surprisingly, many studies did not collect any neuroimaging findings, probably because neuroimaging is often not performed in mild TBI cases.[11],[17],[18],[23],[25],[28],[29],[31],[34],[38]. In relation to other clinical findings, TBI was often accompanied by other soft tissue lesions and limb fractures[16],[21],[22],[29],[35],[36],[37]. Alcohol consumption ranged from 11.7 to 42.3%[15],[16],[23],[24],[29],[36].

Table 5

Traumatic brain injury-related consequences, clinical comorbidities, length of hospital stay, and alcohol intake information in epidemiological studies on traumatic brain injury.

Reference

Neuroimaging findings

Other clinical comorbidities/findings

Hospital stay length

Alcohol intake

Melo et al., 2019[24]

Computerized tomography, n=83 (70.9%) reported no encephalic lesions.

From the remaining patients: (i), n=18 (15.4%) presented frontal lobe lesions; (ii), n=12 (10.3%) presented parietal lobe lesions; (iii), n=7 (6%) presented temporal lobe lesions; (iv), n=4 (3.4%) presented occipital lobe lesions.

Not informed

Not informed

19.7% (n=23) of patients displayed intoxication signs, according to their records. The remaining records did not include any information on patients’ alcoholic statuses.

Marinho et al., 2017[31]

Not informed

Not informed

Not informed

Not informed

De Almeida et al., 2016[11]

Not informed

Not informed

Mean hospital stay length for: (i) 2008: 5.4 days; (ii) 2009: 5.3 days; (iii) 2010: 5.5 days; (iv) 2011: 5.6 days; (v) 2012: 5.8 days. Overall mean length of hospital stays: 5.5 days.

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Vieira et al., 2016[15]

Early diffuse axonal injury and intracranial hypertension signs in computerized tomography are associated with greater mortality

Hypotension, hypertension, hypothermia, hyperthermia, hypoglycemia, hyperglicemia, bradycardia, tachycardia, and hypoxia.

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n=33 (42.3%) patients reported alcohol intake prior the trauma event.

Tavares et al., 2014[32]

Chronic subdural hematoma, n=63 (32.5%)

Acute extradural hematoma, n=49 (25.3%)

Acute subdural hematoma, n=30(15.5%)

Cerebral edema, n=2 (1.0%)

Firearm projectile, n=7 (3.6%)

Depressed skull fracture, n=38 (19.6%)

Intraparenchymal hematoma, n=5 (2.6%)

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De Souza et al., 2013[19]

Study conducted on TBI caused by projectile firearms

Frontal lobe lesion, n=49 (27%)

Temporal lobe lesion, n=45 (25%)

Parietal lobe lesion, n=25 (14%)

Occipital lobe lesion, n=31 (17%)

Facial lesion, n=20 (11%)

Multiple lesions, n=11 (6%)

Tangential TBI, n=29 (16%)

Penetrating TBI, n=152 (84%)

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Santos et al., 2013[25]

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Fernandes et al., 2013[33]

Study did not specify whether lesions were chronic or acute.

Fractures, n=11,125 (2.5%)

Extradural hematoma, n=20,923 (4.8%)

Subdural hematoma, n=27,447 (6.3%)

Focal lesions, n=31,644 (7.2%)

Diffuse lesions, n=159,241 (36.3%)

Subarachnoid hemorrhage, n=1,856 (0.4%)

Non-specified lesions, n=186,742 (42.5%)

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Carvalho Viégas et al., 2013[34]

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Ruy and Rosa, 2011[35]

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Sensory reduction, n=45 (48.5%)

Anisocoria, n=15 (16.3%)

Mental confusion, n=11 (12.1%)

Psychomotor agitation, n=10 (10.9%)

Cardiopulmonary arrest, n=10 (10.9%)

Respiratory failure, n=9 (9.8%)

Seizures, n=6 (6.7%)

ICU clinical complications:

Pneumonia, n=16 (17.3%)

Sepsis, n=2 (2.2%)

Acute renal failure, n=2 (2.2%)

Cerebral hemorrhage, n=36 (38.9%)

Cerebral contusion, n=36 (38.5%)

Cerebral edema, n=23 (24.9%)

Bone fracture of any kind, n=18 (19.6%)

Pneumocephalus, n=12 (12.9%)

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Moura et al., 2011[26]

Study did not specify whether lesions were acute or chronic.

Diffuse axonal injury, n=1 (0.99%)

Extradural hematoma, n=20 (19.82%)

Cerebral contusion, n=18 (17.82%)

Subarachnoid hemorrhage, n=10 (9.9%)

Subdural hematoma, n=6 (5.94%)

Most afflicted cranial sites:

Frontal, n=25 (24.75%)

Temporal, n=12 (11.88%)

Temporoparietal, n=12 (11.88%)

Parietal, n=9 (8.91%)

Occipital, n=6 (5.94%)

Parietofrontal, n=6 (5.94%)

Frontotemporal, n=4 (3.96%)

Temporooccipital, n=2 (1.98%)

Basilar skull fracture, n=2 (1.98%)

At admission:

Headache, n=17 (16.83%)

Vomiting, n=16 (15.84%)

Otorrhagia, n=9 (8.91%)

Coma, n=6 (5.94%)

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Ramos et al., 2010[36]

General nervous system lesion, n=34 (19.9%)

Bone lesion, n=39 (22.8%)

Vascular lesion, n=55 (32.2%)

Multiple lesions, n=26 (15.2%)

Soft tissues, n=7 (4.1%)

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n=20 (11.7%)

Guerra et al., 2010[21]

(Only severe TBI) cases were analyzed)

Diffuse Axonal Injury, n=56 (42.4%)

Swelling, n=74 (56.1%)

Intraparenchymal hemorrhage, n=46 (34.8%)

Subarachnoid hemorrhage, n=41 (31.1%)

Study did not specify whether lesions were acute or chronic:

Subdural hematoma, n=20 (15.2%)

Intraventricular hemorrhage, n=15 (11.4%)

Extradural hematoma, n=14 (10.6%)

Thoracic lesion, n=48 (36.4%)

Skeletal muscle lesion, n=37 (28.0%)

Abdomen, n=21 (15.9%)

Spinal cord, n=6 (4.6%)

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Martins et al., 2009[37]

(Only severe TBI cases were analyzed)

Marshall type I injury, n=22 (2.9%)

Marshall type II injury, n=175 (23.4%)

Marshall type III injury, n=172 (23.0%)

Marshall type IV injury, n=58 (7.8%)

Evacuated mass lesion, n=240 (32.1%)

Non-evacuated lesion, n=30 (4.0%)

Brainstem lesion, n=50 (6.7%)

Subarachnoid hemorrhage, n=267 (35.7%)

Face trauma, n=108 (14.4%)

Cervical spine trauma, n=27 (3.6%)

Dorsal-lumbar spine trauma, n=7 (0.9%)

Thoracic trauma, n=141 (18.9%)

Abdominal trauma, n=70 (9.4%)

Limb trauma, n=204 (27.3%)

(Pupil) Isochoric, n=283 (37.8%)

(Pupil) Miotics, n=30 (4.0%)

(Pupil) Anisocorics, n=347 (46.4%)

(Pupil) Mydriatics, n=83 (11.1%)

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Braga et al., 2008[23]

(Only TBI cases caused by falling from standing height were analyzed)

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Systemic arterial hypertension, n=9 (11.8%)

Epilepsy, n=6 (7.9%)

Alcoholism, n=4 (5.3%)

Diabetes mellitus, n=3 (3.9)

Heart failure, n=3 (3.9%)

Alzheimer’s disease, n=3 (3.9%)

HIV infection, n=3 (3.9%)

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n=11 (14.5%)

Faria et al., 2008[38]

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n=33 (39.3%)

Pereira et al., 2006[27]

Altered CT scan, n=75 (31.0%) out of 242

Altered plain radiography of the skull, n=4 (1.7%) out of 239

Altered conscious level, n=85 (18.1%)

Vomiting and nausea, n=97 (20.6%)

Sleepiness, n=51 (10.9%)

Headache, n=40 (8.5%)

Dizziness, n=18 (3.8%)

Seizures, n=11 (2.3%)

Otorrhagia, n=12 (2.6%)

Epistaxis, n=8 (1.7%)

Diplopia, n=2 (0.43%)

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Melo et al., 2006[28]

(Study conducted on children and teenagers only)

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Not applicable

Melo et al., 2004[29]

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1 lesioned organ, n=117 (66.1%)

2 lesioned organs, n=40 (22.6%)

≥3 lesioned organs, n=20 (11.3%)

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n=27 (4.9%)

Dantas Filho et al., 2004[39]

Marshall type I injury, n=15 (7.28%)

Marshall type II injury, n=63 (30.58%)

Marshall type III injury, n=33 (16.02%)

Marshall type IV injury, n=13 (6.31%)

Focal lesion (operated), n=72 (34.95%)

Focal lesion (not operated), n=10 (4.85%)

Hypo-/Hypernatremia and Hypo-/hypercalcemia, n=130 (63.21%)

Polyuria, n=32 (15.53%)

Bronchopneumonia, n=119 (57.77%)

Urinary infection, n=11 (5.34%)

Sepsis, n=10 (4.85%)

Sinusitis, n=6 (2.91%)

Gastrointestinal bleeding, n=3 (1.46%)

Hypoxia, n=81 (39.32%)

Hypotension, n=39 (18.93%)

Both hypoxia and hypotension, n=22 (10.68%)

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Gusmão et al., 2002[22]

(Only evaluated fatal patients)

Diffuse axonal injury, n=96 (80.0%)

Intracranial hypertension, n=47 (39.2%)

Skull fracture, n=63 (52.5%)

Hypoxic brain injury: (19.2%)

Limb fractures, n=46 (38.3%)

Thoracic trauma, n=42 (35%)

Abdominal trauma, n=44 (36.7%)

Both thoracic and abdominal trauma, n=32 (26.7%)

Pneumonia, n=10 (8.3%)

Purulent meningitis, n=3 (2.5%)

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Koizumi et al., 2001[40]

(Only evaluated children)

Skull fractures, n=1,800 (11%)

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<1 day, n=333 (2.0%)

1 to 3 days, n=12,100 (73.9%)

4 to 7 days, n=2.825 (17.3%)

8 to 29 days, n=1.023 (6.2%)

≥30 days, n=95 (0.6%)

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Koizumi et al., 2000[20]

Fracture of skull vault, n=45 (1.2%)

Basilar skull fracture, n=32 (0.9%)

Other skull fractures, n=22 (0.6%)

Multiple fractures of skull/face, n=4 (0.1)

Brain concussion, n=1038 (28.6%)

Cerebral laceration and contusion, n=192 (5.3%)

Hemorrhage, n=509 (14.0%)

Traumatic intracranial lesion of other types, n=1793 (49.3%)

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Most predominant hospital stay duration is of 1 to 7 days hospitalized (n=2,637; 72.5%).

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Colli et al., 1997[16]

Plain radiography of the skull: 18.0% (24% of 73%) presented fractures.

CT scan: 4.2% (30% of 14%) presented brain lesions

Scalp lesion: 66.2%

Headache (21.4% of children)

Vomit: 17% (approximately in adult and children)

Headache: 17% (approximately)

Alteration of consciousness (some time after TBI): 24.4%

Alteration of consciousness (immediately afterwards): 87%

Soft tissue lesion: 17.9%

Face lesion: 15.4%*

*Full text was not retrievable. Figure 7 was missing

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17% of adults (approximately)*

Gennari et al., 1995[17]

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Penetrating trauma, n=32 (32%)

Blunt trauma, n=68 (68%)

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Masini et al., 1994[30]

Chronic subdural hematoma, n=54 (1)

Acute extradural hematoma, n=40 (0.7%)

Acute subdural hematoma, n=40 (0.7%)

General fractures and basilar skull fracture, n=58 (1%)

Cerebral contusion, n=56 (1%)

Firearm projectile induced lesion: 19 (0.4%)

Intracerebral hematoma: 9 (0.2%)

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n=64 (64%) were discharged <24 hours.

n=16 (16%) stayed longer than 7 days.*

*Independent 100 people sample 71.6% patients

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Maset et al., 1993[18]

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Average hospital stays: 4.65 days

71.6% patients stayed for a maximum of 4 days.

24.9% patients stayed for 2 days.

1.7% patients stayed for a period greater than 20 days.

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TBI: traumatic brain injury



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DISCUSSION

In the present study, we evaluated the sociodemographic and clinical characteristics of patients with TBI admitted to a public reference trauma center in Minas Gerais, Brazil. This is the first study to perform such evaluation in the state of Minas Gerais, specifically at one of the largest reference trauma centers in Brazil. It is worth highlighting the large number of patients admitted to this center in a short period of time. The hospital admitted almost 17 patients with TBI every day. Young men were most commonly affected, and unspecific falls were the most common cause of TBI. Overall, these findings are consistent with the results of other Brazilian studies, as shown in our systematic literature review [11],[15] - [40].

The higher vulnerability of men can be explained by sociocultural and behavioral factors, such as higher exposure to urban violence than women[25]. A European systematic review found a preponderance of men in 28 studies in which the male-to-female ratio ranged from 1.2:1.0 to 4.6:1.0[41]. Accordingly, men in the United States have higher age-adjusted rates of emergency department visits and deaths related to TBI[4]. In our sample, TBI occurred more frequently in young adults, with mean ages ranging from 22 to 49 years in different studies[25],[41],[42].

In contrast to most Brazilian reports, the current study found that falls were the main cause of TBI, but not traffic accidents[29],[43]. One of the largest epidemiological studies conducted in the Brazilian population found that falls were the most common TBI mechanism, similar to our findings[33]. Falls were also the most common cause of TBI in European countries and in the USA[4],[41].

Approximately 19% of our sample reported having consumed alcohol prior to the traumatic event. Our results show that falls, followed by traffic accidents, were the main causes of TBI in patients under the influence of alcohol. Falls were also the main cause of TBI in patients under the influence of illicit drugs (mainly marijuana and crack), but here traffic accident was followed by physical aggression. It is known that the use of alcohol and illicit drugs favors the occurrence of risky situations[29]. In an American study, it was found that both alcohol and illicit drug use were common before a TBI[43]. In Brazil, it is still unclear what role alcohol and other drugs play in TBI[36]. Most of the studies included in our review did not evaluate alcohol status of patients, and those that did had missing data on such information[15],[16],[23],[29],[36].

Regarding the severity of TBI, as determined by the GCS, the majority of our sample was diagnosed as mild (87.4%). Mild TBI was also the most common severity level in the Brazilian studies examined, but studies differed in their sample composition. For example, Marinho et al. analyzed a group of 18-30-year-old individuals - an age group more prone to riskier situations and to moderate and severe TBI[29],[31],[43]. Faria et al. grouped severe and moderate TBI together and yet accounted for only 52% of the total cases[38].

The clinical meaning of mild TBI should not be underestimated, as it has been associated with the development of cognitive and behavioral changes[44]. According to one scoping review, half of patients with a single episode of mild TBI develop long-term impairments in several cognitive domains, including executive functions, learning/memory, attention, processing speed, and language[45]. This review included heterogeneous studies using different cognitive batteries in mild TBI patients at different time points after the traumatic event, which may explain the high rate of cognitive deficits. For example, significant episodic memory deficits can already be observed in the acute phase of mild TBI[46].

Neuroimaging is an important tool in establishing the prognosis for TBI. Seventy-six of 436 (17.4%) patients had early tomographic/neuroimaging TBI-related alterations. It is well known that the more severe the TBI, the more likely the patient is to have neuroimaging changes[47]. Our results confirm that more than half of the patients with moderate or severe TBI had cranial CT changes. Conversely, about 10% of patients with mild TBI had neuroimaging changes. Few of the Brazilian studies reviewed included their neuroimaging findings, as neuroimaging is not considered cost-effective due to the low rate of positive neuroimaging findings in mild TBI[48].

The length of hospital stay was less than 24 hours in 73.6% of the cases, as most were mild TBI cases. Conversely, a GCS score of 12 or less on admission, as well as neuroimaging changes and medical comorbidity (i.e., both clinical and psychiatric conditions), were associated with a longer hospital stay. Similar to our results, Sorensen et al. found that lower GCS score and psychiatric comorbidity were significantly associated with delay in hospital discharge in patients with TBI[49]. The length of hospital stay in our systematic review varied widely, probably due to the heterogeneity of the sample and the different protocols for treatment and management of TBI in different clinical settings.

In the current study, 3.6% of our post-TBI patients died (n=18). Mortality rates should be interpreted with caution, considering the heterogeneity of epidemiological studies on TBI. For instance, Fernandes et al. found a mortality rate of 12.0% in a much larger sample that included over 400,000 records from a much longer time window[33]. In Europe, there is also a wide variation in post-trauma mortality rate, ranging from 3.0/105 inhabitants per year in both Hannover and Münster (Germany) to 18.3/105 per year in Finland and Italy[41]. In the USA, about one third of all related deaths are diagnosed with TBI[50].

There are limitations to the present study. Some variables (e.g., level of education) were not available for a significant percentage of patients, reflecting the challenges of clinical data collection in a busy trauma center, and thus preventing a more thorough analysis. Medical records also did not include categories of falls. We were only able to capture serious sequelae during hospitalization, which prevented us from exploring less severe complications, including cognitive, behavioral or motor symptoms, and the associated impact on patients’ lives. In addition, the present study was conducted in a time window of one month within one year - which was one of the main reasons that led us to conduct a systematic review. From the literature review, we obtained an accurate snapshot of TBI epidemiology in one of the main trauma centers in one of the largest metropolitan regions of Brazil. We chose the month of July because of winter break - a time of year in which people are more exposed to risky situations (such as car travel) and, consequently, to TBIs.

Future studies with a comprehensive longitudinal evaluation of TBI beyond the acute phase are warranted. The investigation of regional specificities in TBI profile in other Brazilian regions and other developing countries could also provide meaningful clinical and epidemiological information. Only with robust evidence can optimal prevention and rehabilitation measures be implemented, influencing the outcome of this daunting problem.


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Conflict of interest:

There is no conflict of interest to declare.

Authors’ contributions:

ALGM: collected data; JLVMB, MGFC: drafted the manuscript; MGFC, NPR: conducted the statistical analyses; RMF, LCS: proofread the manuscript; ALSM, ALT: designed the study.


Support

This article received financial support from 2016 NARSAD Young Investigator Grant from Brain & Behavior Research Foundation (grant #25414), 2019 “For Women in Science”- L’Oreal Brazil-UNESCO- Brazilian Academy of Science (ABC), FAPEMIG (Fundacção de Amparo aà Pesquisa do Estado de Minas Gerais, Brazil), CNPq (Conselho Nacional de Desenvolvimento Cientiífico e Tecnoloígico, Brazil) and CAPES (Coordenacção de Aperfeicçoamento de Pessoal de Niível Superior).



Address for correspondence

Aline Silva de Miranda

Publication History

Received: 01 April 2021

Accepted: 07 August 2021

Article published online:
31 January 2023

© 2022. Academia Brasileira de Neurologia. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commecial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/)

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Zoom Image
Figure 1 ROC curve of the logistic regression model (AUC=0.819).
Zoom Image
Figure 2 Flowchart of study selection process.TBI: traumatic brain injury.